高氯离子低COD矿井水中COD的测定方法探讨

由于煤矿地理分布和地质构造原因,我国部分煤矿矿井水中氯离子含量较高。矿井水经混凝、沉淀、过滤处理后,其中的COD含量通常较低,采用重铬酸钾国家标准方法测定处理后的高氯离子矿井水中的COD过程中,水样中存在的氯离子极易干扰测定结果。当水样中氯离子含量超过2 000 mg/L时,采用国标方法所测数据几乎不具参考价值。针对高氯离子矿井水水质特征,通过对比试验方法研究了低浓度重铬酸钾氧化法在高氯离子低COD矿井水中COD测定的应用,其结果有效扩展了国家标准方法的测定范围,为煤炭行业矿井水COD检测分析提供了科学依据。

DISCUSSION ON THE METHOD OF DETERMINING COD OF MINE DRAINAGE WITH HIGH CHLORINE-ION AND LOW-COD

Because of the difference of geographical distribution and geological structures,the chlorine ion concentration in mine drainage is high in some mine areas.Chlorine ion could disturb the COD measurement results of mine drainage especially with high chlorine and low-COD.According to the national standard methods,the COD measurement results of mine drainage do not have the reference value when chlorine ion concentration is higher than 2000 mg/L.To solve the problems,the application of oxidation process with low concentration to the high-chlorine and low-COD mine drainage was tested in this paper,which extends the measurement ranges of national standard methods.